Swedish authorities now suspect Pirate Bay co-founder Gottfrid Svartholm Warg of serious fraud and another data intrusion in addition to the alleged hacking of IT company Logica that led to his arrest, public prosecutor Henrik Olin said Monday.

Svartholm Warg was arrested in Cambodia in August and deported to Sweden. In September, Swedish authorities arrested him on suspicion of hacking Logica, which handles taxes for the Swedish government. Since then, his detention has been extended by a court every fortnight.

"On Friday, he was detained for another two weeks," said Olin. But this time he was also detained on suspicion of additional crimes. "We added new suspicions of new crimes," Olin said.

Olin did not want to be specific because of the sensitiveness of the investigation, but said the alleged data intrusion and fraud are not linked to the Logica hack.

"The fraud is linked to this data intrusion," said Olin. Svartholm Warg is suspected of "aggravated fraud", a more serious crime, he added.

Aggravated fraud could, for example, involve a large amount of money, false documents or a systematic fraud scheme, said Olin, who was quick to add that these were mere examples, not necessarily related to the new suspicions about Svartholm Warg.

Svartholm Warg hasn't been charged with anything yet, said Olin. The investigation into Warg's alleged role in the theft of sensitive tax records from Logica is still ongoing. "In the Swedish system, he will not officially be charged before the preliminary investigations are over," Olin said, adding that the Logica investigation is now concentrating on IT forensics.

After Svartholm Warg's arrest in Cambodia, many expected that he was sought by the Swedish government because he still had to serve a prison sentence for his role in creating the Pirate Bay. He and the other Pirate Bay founders were convicted for copyright related offenses, fined and sentenced to prison for their involvement in the creation of the popular torrent-tracking site. Svartholm Warg later missed an appeal hearing, pleading illness, and moved to Cambodia.

While Svartholm Warg is in prison, the time served is deducted from his one-year Pirate Bay prison sentence, said Olin. He expected to return to the court within two weeks to ask for another extension of Svartholm Warg's detention.

Loek is Amsterdam Correspondent and covers online privacy, intellectual property, open-source and online payment issues for the IDG News Service. Follow him on Twitter at @loekessers or email tips and comments to loek_essers@idg.com